Sulfenamide inhibitors are especially potent for vulcanizable rubber compositions containing sulfenamide accelerators but are less effective when the accelerator is 2-mercaptobenzothiazole or bis-2-benzothiazolyl disulfide. Acid retarders reduce scorchiness of benzothiazole accelerated stocks by adversely affecting both the cure rate and the extent of cure. A study of the mechanism of retarders in rubber vulcanization lead to a class of retarders consisting of hydrocarbylthio derivatives of trialkylsulfonyl methane, J. Appl. Poly. Sci., Vol. 16, pages 2647-2655 (1972), however, these retarders have not gained acceptance. Therefore, there is a need for more effective inhibitors for benzothiazole accelerated stocks.